> What exactly would you expect to change when nothing has actually changed yet?

This is my view point:

Reputable well known economists and analysts: "If the UK votes to leave then the UK will suffer great economic consequences. As soon as in the 3rd and 4th quarter of 2016 the UK will see a recession which will continue into 2017, 2018, ..."

A few months later the same people: "OK, 2016 was actually quite solid, but 2017 the shit will hit the fan"

A few months later the same reputable people: "OK, it seems like we need to make some corrections to our prognosis. There will be no recession, not even in 2017, but the economy will definitely not grow as fast as it would otherwise."

Me: "Why is still everyone hysteric. Seems like nobody knows what is really going on. Nothing bad happened yet. Let's chill and watch"

People from before: "Of course nothing has happened yet!!! Why did you think something should have happened by now? Who did tell you that, ey?"

Me: -.-

The Pounds fell as an immediate result. Since then the economy has been held up by very strong consumer spending which can only last so long in the face of rising prices and increased capital inflows taking advantage of the weaker pound.

The decline is not going to be sudden it'll be a gradual thing as companies move staff out and new investment fails to happen.

I'm guessing that your let's chill and watch comes from a secure position. There are people who 10% increases in prices makes a massive difference and they can't afford to just 'chill and watch.' This is going to have very big consequences.

The IMF said in 2015 that the pound was up to 20% overvalued though. I recall people talking about it being overvalued for many years before that - in fact, the pound being so highly valued (which was great for the financial industry but not that much else) probably led to a lot of the deindustrialisation over the last few decades which is probably where a lot of this really started.

Anyway, the U.K. is a fairly large advanced economy, and as a bystander outside the U.K., US and Europe, I find it pretty far fetched that what you say will occur, and that the U.K. will have problems long term outside the EU. There might be some short term pain but it's probably for the best long term.

The pound has been 20% overvalued for 30 years?

I'm struggling to see why being outside of a large trading bloc is better than being inside a large trading bloc. You've said it is better off long term so there must be advantages to being outside.

EDIT

Just to clarify the UK exports much more in services to the EU than it imports from the EU. Services are exactly the type of thing that the EU is different from other trade deals. The UK loses what it has a surplus on and has to pay more for all the goods that it has to import.

As we are all guessing what might be: How about - Brexit as a stunning own-goal. The english can take their ball but the game will go on. Germany now the biggest contributer to the EU have unprecedented leverage in a lopsided eurocentric parliament over the other states including France (beneficiary) to forge a new closer, more centralised Europe solving many of the issues of the old. They must be rubbing their hands with glee. They folded! They walked away! New treaties are signed. There is no deal with Britain and no compromise. The time expired and they come back empty handed, a hard Brexit on the terms of the old treaties. No more pesky englanders to thwart every move to a superstate with a market of 650+ million people. When Europe speaks old allies of Britannia will heed and shrug their shoulders at their erstwhile master. Power and influence will drain as Britain becomes a poundshop, surrounded by EU states, international flights flying overhead. Shannon will become the US-Europe air hub Heathrow's new runways now unused car lots. Money will flow outwards from the City to Berlin the centre of the new Europe. The best minds will simply follow the money and leave the doomed vessel. Europe will use their sheer weight against the rump state at every turn until one day cap in hand it will return, new capital - Edinburgh... or it might work out great.